Feature: Meeting lifecycle — Prep → Meeting notes → Done

Reported by @lsto

Description:
When prepping a 1-1 meeting, it would be great to transition from Prep → Meeting notes → Done in a structured way. During the meeting, users want to jot down notes alongside the prep. The capture panel could potentially be reused here.

Use case:

1. Generate/write prep notes before the meeting
2. During the meeting, transition to a "running the meeting" mode where you can add notes in real-time
3. After the meeting, mark it as done

This would make the flow: Prep → Meeting notes → Done rather than just editing the prep notes.

Start by locating the existing meeting prep flow and the capture panel mentioned in the issue. Define how users move from Prep to live meeting notes to Done, including how notes are added during the meeting; the feature is complete when this full lifecycle is supported.